Global Surface Water Explorer Jean-Francois Pekel, Andrew Cottam, Noel Gorelick* and Alan Belward EC Joint Research Centre, *Google European Commission/ Google Earth Engine Side Event: GEOGLOWS and the Harmonization of GEO Water Activities

Global Surface Water Explorer Mission / Objectives and Goals Mission To produce maps and statistics documenting when and where the Earth’s land surface has been covered by water during the past 32 years at 30m resolution Objectives Globally consistent set of maps, fully validated, distributed with free-and-open access license and easily accessible through an interactive web interface Goal Map all open water surfaces (inland and coastal) at global scale, every month of every year at a spatial resolution of 30m. Produce a set of thematic products documenting different facets of the surface water dynamics.

Global Surface Water Explorer Geographical Scope Methodology Expert system applied to global Landsat L1T archive at the pixel scale (1.8 PB data), accompanied by validation protocol Global Project Governance Structure Collaboration between EC Joint Research Centre and Google Earth Engine. Longer-term goal is transition to Copernicus Global Land Service

Global Surface Water Explorer Significant achievements in 2016-2017 Achievement 1 Changes in global surface water at 30m resolution; variations in persistence and location between March 1984 and October 2015; gain, loss and constancy in persistence (1984-2000-2015); recurrence (frequency with which water reappears from year to year); annual seasonality; transitions among permanent water, seasonal water and land classes between first and last year of observation; maximum surface water extent; annual / monthly water history at pixel scale; change measurements at global, continental, and country scale. https://global-surface-water.appspot.com/ Pekel, J-F. et al., (2016) Nature 540, 418–422 doi:10.1038/nature20584

Global Surface Water Explorer Plans and Deliverables for 2018-2019 Deliverables - Annual permanent surface water area and trends by country (with estimate of uncertainty) 1984 – 2015 - Coastal erosion/accretion - Natural / artificial water body identification General Plans - Update time series to end of 2017 - Produce 20m resolution using Sentinel 2 and Landsat - Move towards operational product generation

Global Surface Water Explorer Plans for cross SBA linkages and SDG support Links to other SBAs or initiatives UNFCCC: Global Climate Observing System (2016 Plan), Lake Area essential climate variable CBD: Ecosystem function (inundation) Sustainable Development on our Human Planet (GEO) UNCCD: Part of 14 point land degradation classification (World Atlas of Desertification) Contributions to SDGs Indicator 6.6.1 Change in the extent of water-related ecosystems over time Indicator 15.3.1 Proportion of land that is degraded over total land area (indirect) Target 15.5 Take urgent and significant action to reduce the degradation of natural habitats... Challenges and Issues: Data handling is still a challenge at petabyte scales, Landsat archive consolidation still needed, global scale Sentinel 2 a and 2 b still to be integrated GEOGLOWS and the Harmonization of GEO Water Activities

Thank You Jrc-surfacewater@ec.europa.eu